Combined vacuum tube and transformer



March 20, 1928. 1,662,891

A. MUTSCHELLER COMBINED VACUUM TUBE AND TRANSFORMER Filed Jan.l4, 1921 2 Shams-Sheet 1 l WRE1 INVENTOR March 20, 1928.

A. MUTSCHELLER COMBINED VACUUM TUBE AND TRANSFORMER Filed Jan. 14, 1921 2 Sheets-Sheet 2 JELJRE 5 ATTORNEY 3 iii 4, l

Patented Mar. 20, 1928. v

UNITED STATES ARTHUR MUTSCHELLER, OF NEW YORK, N. Y.

COMBINED VACUUM TUBE AND TRANSFORMER.

Application filed January' 14,' 1921. Serial No. 437,195.

My invention relates to vacuum tubes and transformers used in connection with the vacuum tubes, for energizing the same.

Heretofore in this art it has'been customary to energize vacuum tubes, for instance X-ray tubes, by means of high tension currents supplied by step-up transformers, but

the vacuum tube has alwavs been separate and distinct from the transformer, the vacuum tube and the transformer thus being separate units or instruments.

In consequence of the separation of the vacuum tube and the transformer, it has been necessar to connect these parts by means of con uctors, and naturally in these conductors the voltage developed with the apparatus in action has been very high.

The result has been that the vacuum tube and transformer, with their connections, 2 have been quite bulky and cumbersome.

Not only that, but there has been considerable diiliculty in insulating the conductors extending from the transformer to the vacuum tube, and in preventing accidental discharges from taking place from the terminals of the vacuum tube and even from certain portions of the transformer. It has been impracticable to thoroughly insulate the various metallic parts here contemplated without rendering them so unwieldly as to greatly impair their efliciency.

What I seek to do by my invention is to combine the vacuum tube and transformer into a single unit of small size, the transformer being practically contained within the tube and carried thereby.

By virture of this arrangement, I attain a number of advantages, among which are the following:

I. All exposed high tension wires are completely eliminated, so that all chance for the operator or a patient to receive a dangerous shock is in practice reduced to a nullity.

II. The complete unit, comprising both the vacuum tube and the transformer, occupies less space than the vacuum tube alone has heretofore occupied, allowance being made for the space taken up by the exposed terminals heretofore employed.

III. The construction is greatly s1mpli--- be approached more closely without danger; and if the vacuum tube be an X-ra tube, it may without danger to the patient lie placed closer to his body than has been the case heretofore.

V. The cost of construction and installation is greatly reduced, and in the case of an X-ray tube used in close proximity to the patients body, the energy required to pass a given quantity of rays through the body or a portion thereof is lessened.

Reference is made to the accompanying drawings, in which like reference numerals indicate like parts throughout the several figures.

Figure 1 is a view partly sectional and partly diagrammatic, showing my invention as used with an X-ray tube of the rarefied gas t pc and provided with a radiator, the trans ormers being located directly within the rarefied gas with which the tube is filled.

Figure 2 is a sectional view showing an X-ray tube carrying two transformers, which are located in separate compartments having no communication with the rarefied gas or vapor contained within the tube.

Figure 3 is a view partly sectional and partly diagrammatic, showing an X-ray tube of the Coolidge type and its immediate connections, all as arranged for dental work and made in accordance with my invention.

Figure 4 is a view partly sectional and partly diagrammatic, showing my invention as used with an X-ray tube and connections so arranged as to permit the use of the tube with alternating currents and with synchronizing mechanism for rendering ineffective the current impulses flowing in one direction.

Figure 5 is-a fragmentary section of a form of my device in which provision is made for regulating the current passing through the vacuum tube, by means of apparatus carried by the vacuum tube and housed therein.

Referring to Figure 1, the body portion of the X-ray tube is shown at (S, and carries two neck portipns 7, 8 integral with it. A gas pressure regulator appears at 9, and may be of the usual or any desired construction.

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ported by a stem 13 of soft iron, which thus serves the purpose of a cathode stem. Similarly the anti-cathode 11 is provided with and supported by a stem 14 made of soft iron.

Encircling the stem 13 is a sleeve of insulating material, and similarly encircling the stem. 14: is another sleeve 16, also of insulating material. The sleeve 15 carries a winding 17 of coarse wire, constituting a primary winding, and another winding 18 ike'it is mounted upon the sleeve 16. The windings 17 18 are encircled by sleeves 19, 20 of insulating material. A secondary winding 21 is mounted upon the sleeve 19, and another secondary winding 22 is mounted upon the sleeve 20. The windings 21, 22 are provided with coatings 23, 24: of insulation. Radiator members 25 are supported upon the stem. 14 and held in position by a fastening 27.

The neck portion 7 of the tube is provided with a seal 26, and extending through this seal and connected with the primary winding17 is a wire 28. Another wire 29 ex tends through the seal and is connected with the primary winding 17. The wire 29 also extends through a seal 26 carried by the neck portion 8 ofthe tube, and is connected with the primary winding 18. A wire extends through the seal 26 and is connected with the primary winding 18. The wires 29 and 30 are the primary leads whereby the device is energized, and the currents through these wires are of relatively low voltage.

@ne end of the primary winding 17 is by a short wire 17* connected with the adjacent end of the secondary winding 21, and the opposite end of this secondary,..winding is "connected by a short wire 17 with the cathode 10 The secondary winding 22 is at one of its ends connected with the anticathode 11 by means oi a short wire 18. The secondary winding 22 is also connected by a wire 18- with the adjacent portion of the wire 29;

A circuit through theprimary windings may be traced as follows: WV ire 28, primary winding 17, wire 29, primary winding 18, wire 30 to source of supply (not shown), and thence to wire 28. This energizes ie two secondary windings 21, 22, and causes them to inagnetize the stems 13, 14., so that they act as transformer cores, and such, cooperate with the primary windings ducing rents in tne sectherefore desirable that the evacuation of the tube be sufiicient to afiord proper insulation for the secondary windings, at least under normal working conditions. The heat radiated by the radiator members 25 tends to keep the secondarywinding 22, associated with the anti-cathode, from becoming unduly heated. This action also improves the insulation of the secondary winding 22, by keeping down the temperature of the rare fied gas within the neck portion 8. lit the tube be used carefully and only with exciting currents such as will cause discharge of unitary direction between the anode and the cathode, no difficulity is experienced in consequence of undue heating of the cathode.

The X-rays are radiated from the anticathode, and particularly from the tungsten target, in the-manner well known in this art.

The form of my device appearing in Fig ure 2 differs from that of above described chiefly in the means employed for insulating the secondar windings. The body portion of the X-ray tube appears at 82, and connected with it are two neck portions 33, 34- These neck portions are provided with closure seals 35, 36. The tube is provided with gas pressure regulator 53'? Located within the neck portions 33, 8d are two stems 38, 39 made of soft iron and capable of servingv as transformer cores. These stems are respectively encircled by two sleeves d0, 41 of insulating material, and wound upon these sleeves are two windings 4 2, ot coarse wire, serving as primary windings. Two secondary windings are shown at 44, 45, and are so mounted to encircle the primary windings nd associated therewith.

ndings are provided insulating material.

cathode is shown at m the core 38.

t 49, is carried seals 50, 51, connec. cathode and'anti-c a with 43 is similarly provided with terminals 56, 57. The secondary winding 44 is at one of its ends connected with the primary winding 42 by a short wire 58, and is connected at its other end with the cathode 48 by means of a short wire 59; The secondary winding 45 is at one of its ends connected with the anti-cathode 49 by a short wire 60, and at its other end it is connected with the primary winding 43 by means of a short wire (51.

The neck portions 33, 34:, together with the walls 52, 53 are essentially hollow bodies, containing chambers 62, 63, these chambers being filled with insulating material, preferably an oil or a wax composition suitable for the purpose. The insulating oil or was: composition has a tendency to prevent the undue development of heat in the primary windings, and on this account no radiator mechanism is necessary with this form of my device. That is to say, the oil or wax tends to distribute the heat evenly, and'thus tends to prevent the temperature at any par ticular point from becoming very high as j ared with other points. desired the oil or insulating wax com position can be omitted, and the chambers exhausted by -means of an air pump to such degree as to thoroughly insulate the secondary windings. For this purpose the exhaustion may be carried much further than the degree of exhaustion required for the space between the anode and the cathode.

The external connections for the X-ray tube shown in Figure 2 may be the same as those above described for the form shown in Figure 1, or they may be varied indefinitely to suitthe needs of particular cases.

in Figure 8 1 show a special form of X- ray tube, combined with a special form of transformer contained within the X-ray tube, also certain external connections associated with the parts mentioned and having particular advantages, This apparatus is especially adapted for dental work, but may be used in other relations as occasion may reonire The iii-ray tube appearing in Figr3 o v r 1 m r 1 A .1 nre i so-calieu s, huge type, and i be is a s nsforrner housed within the ti.

- e sformer.

Extending rrom the spheroidal portion 63 is a neck 68 made of glass, and extending axiallythrough this neck portion and integral therewith is a stem (59. A glower cathode 70, having the form of a filament and adapted to be heated to incandescence is shown at T0 and supported by the stem 69. This stein also supports a concave reflector 71. The anti-cathode appears at 72, and is mounted upon a core 73, made of so'it'iron and serving the double purpose of an anticatliode stern and a transformer core. The member 73 is provided with a portion 7% having the general form of a stirrup and integral with it, so as to form, with the member '13, a closed core.

Encircling the stem '73 is a tubular sleeve. 75 of insulating material, this sleeve carrying a primary winding 76. ldncircling t'lliS primary winding is a tubular sleeve 77 of insulating material, and mounted upon this tubular sleeve is a winding '78, constituting the secondary winding and having a covering- 79 of insulating material. A platinum seal 80 engages the stem '73 and the wall 64, so as to form a gas tight connection be tween the chambers 65, 66. Two wires 81, 82 are connected with the glower filament TC, and for this pur'pose extend through the stem 69. The wire 81 is connected with secondary winding 83, forming a part or transformer 84-. The winding 83 is by wire 85- connected with the wire 82, and also with the wire 86 leading to the ground at 8?. The primary winding of the trans i'oriner 84 is shown at 8?. The transformer 84L is for the purpose of supplying currents to the glower cathode 70 for the purpose of heating the same to incandescence.

The primary winding 88 is connected with a wire 89, leading to a main 90. A wire 91 leads from the primary winding to a O0 switch $2 and from he latter a wire 93 lead to main 94. A wire is connected w th J time ground windi of supplying currents to the glower cathode 70, for the purpose of heating the same.

A circuit:through the primary winding of the transformer 84 may be traced as follows: main 90, wire 89, primary winding 88, wire 91, switch 92, wire 93, main 94, to source of alternating current supply, and thence back to main 90.

The secondary circuit of the transformer 84 may be traced as follows: secondary winding 83, wire 81, glower cathode 70, wire 82 and wire 85, back to secondary winding 83. The circuit just traced is for the purpose of heating the glower cathode 70.

The primary circuit through the main transformer may be traced as follows: main 90, rheostat 99, wire 98, primary winding 76, Wire 97, switch 96, wire 95, main 94, to source of alternating current (not shown) thence back to main 90.

The secondary circuit of the main transformer may be traced as follows: secondary winding 78, short wire 102, stem 73, anticathode 72, glower of filament 70, wires 82, 86, to ground at 87, thence from ground at 104 to wire 103, and wire 97 and short wire 101 back to secondary winding 78. The circuit just traced is the main or high potential circuit for producing discharges between the electrodes and causing the emission of the X-rays.

The cathode being always at zero poten tial, because grounded as above explained, the potentials developed in the main or secondary circuit are necessarily so apportioned as to be reckoned from zero.

The closed-core transformer used in this form of my apparatus presents all of the known advantages of a closed core transformer, notwithstanding the fact that the transformer is located entirely within and carried by the Xray tube.

In the form or my device shown in Figure 4, the globular portion'ot the X-ray tube appears at 105, and the gas pressure regulater is shown at 106. The neck portions of the tube are shown at 107, 108, and are provided with closure plugs 109, 110. The body portion 105 is provided with a short extendingportion 111 having a general annular form and closed by a plate 112 of transparent glass. The body portion 105 is made of lead glass, and quite thick, so as to render it as far as possible impervious to the X-rays, which, however, can pass freely through the window 112. The tube is provided with curved walls 113, 114 integral with the body portion 105 and neck portions 107, 108. The cathode is shown at 115 and the anticathode at 115 these parts being supported repectively upon sot-ft iron cores 117, 118. The primarywindings 119, 120 encircle the cores 117, 118 and are insulated therefrom by bushings 121, 122. The secondary windings shown at 123, 124, and

encircle the primary windings. The secondary winding 123 is by a short wire 125 connected with the cathode 115. The secondary winding 124 is by a short wire 126 connected with the core 118, and hence with the anticathode 116. Connected with the primary winding 119 are wires 127, 128, the wire 127 being also connected with the primary winding 120. The secondary winding 1s by a short wire 131 connected with the wire 127, and the secondary winding 124 is by ashort Wire 132 similarly connected with the wire.

At 133 is shown a syncln'onously-operated switch; that is, a switch operated in synchronism with the alternating current whereby the apparatus as a Whole is energized. As such synchronously-operated switches are commonly known in this art, and as the construction of the switch is not a part of my invention, I make no effort to show the switch construction in detail, but content myself with a diagrammatic representation of the switch. Two electrodes 134, 135 are actuated by a member 136 which is moved in synchronism with the current. There are four contact members 137, 138, 139, 140, so arranged that at one moment during each cycle the electrode 134 engages the contact member 137 while the electrode 135 engages the contact member 139, and at another moment duringeach cycle the electrode 134 engages the contact member 138 while the electrode 135 engages the contact member 140. A wire'141, from the contact member 139, is connected with the wire 130. A. wire 142 is connected withthe contact member 140, and with the wire 128. Alternating current its-supplied to the switch by means of leads 143, 144, which are connected with the electrodes 134', 135 respectively. A wire 1.45 is connected with wires 128, 142, and with the contact member 137. A wire 146 is connected with the wires 130, 141 and also with the contact member 138.

The general relative action of the primary windings and secondary windings is the same in the apparatus shown in Figure 4 as that above described with reference to the apparatus shown in Figure 1. However, in the apparatus shown in Figure 4 the wiring used for energizing the primaries is arranged somewhat differently, as above described. The purpose oi": arranging the wiring as just described with reference to Figure 4 is to enable the synchronously-operated switch 133 to avoid reversal in the direction of the flow of the current through the primary windings each time they are energized, or in other words, each time a reversal takes place in the flow of the alternating current. By doing this, the several successive secondary currents produced are of unitary direction, this direction being such that the discharges produced. have the proper direction for the eflicient generation of X-rays.

With the switch 133 occupying the position indicated by full lines in Figure 4, a primary circuit may be traced as follows: lead 144) electrode 135, contact member 139, wire 141, wire 130, primary winding 120, wire 127, primary winding 119, wire 128, wire 145, contact member 137, electrode 134, lead 143, to source of alternating current supply (not shown), and thence back to lead 144. The primary circuit thus traced energizes the apparatus, and causes a discharge to take place between the cathode and the anticathode, in the secondary circuit.

Following the action further, I will assume that the switch 133 now so actuated that the electrodes 134, 135 are disengaged from the contact members 137, 139, and brought into engagement with the contact members 138. 140; this being done at the instant when the reversal takes place in the alternating current.

Another primary circuit may be traced as follows: lead 144, electrode 135, (now in a new position), contact member 140, wire 142, wire 128, primary winding 119, wire 127, primary winding 120, wires 130, 146, contact member 138, electrode 134 (in its new position), lead 143 to source of alternating current, thence back to lead 144.

lit will be noted that in the circuit just traced the current passes through the primary windings in the same direction of flow as before. Hence the discharge or secondary current has the same direction as before. The result is that the flow of current in both directions is utilized, or in other words that both parts of the alternating current are rendered available, the discharge having a unitary direction, which it maintains so long as the switch 133 continues to operate in synchronism with the alternating current. I

In the form of my device shown in Figure 5, I provide sim 1e mechanism, carried by the X-ray tube, or enabling the operator to adjust within reasonable limits the voltage and amperage of the currents used for heating the glower cathode; and I also provide mechanism, contained within and carried by the tube, f r generating the currents time used for heating the cathode.

The globular portion of the X-ray tube appears at 148, and is provided with a neck 149, these and adjacent parts containing an oil chamber 150 or some equivalent thereof as above contemplated. A glower cathode is shown at 151, and is connected with an inductive winding 152; engaging this winding is a slide 153 of metal, carried by a rod 154 of insulating material and used for the purpose of short circuiting two or more turns of the coil 152. The rod 154 extends through a neck 155 which is oil tight. The

bperator by grasping the rod 154 and moving it in or out to any desired extent, can virtually vary the number of turns of wire in coil 152. By doing this he can control the voltage and amperage of the currents supplied to the glower cathode. The coil 152 is housed within a tubular core 156 of soft iron. and this tubular core carries a reflector 157, this reflector being located in close proximity to the glower cathode. The tubular core 156 carries a sleeve 158 of insulating material, and upon the sleeve is the primary winding 159. The secondary winding is shown at .160. A short wire 161 extends from the primary Winding to the sec ondary winding and another short wire 162 extends from. the secondary winding to the tubular core.

In practice the secondary winding 160 is energized inductively from the primary winding and the tubular core, and the coil J2 within the tubular core is energized inductively therefrom. Thus the currents used for heating the glower cathode are generated by virtue of a true transformer action, the coil 152 being in effect located in a secondary circuit or". a transformer carried within and constituting practically a part of the X-ray tube.

Except as otherwise noted the X-ray tubes shown in Figures 4 and 5 are similar in construction and action to the one appearing in Figure 1 While I show and describe my invention as embodied in certain specific forms, I wish it understood that these forms can be varied within wide limits without departing from my invention, the scope of which is commensurate with my claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is as follows:

1. A device of the character described comprising a vacuum tube having a plurality of portions integral therewith, one of said portions being fashioned into a discharge compartment and the other of said portions being fashioned into an oil compartment, and a transformer and a volume of oil lo cated within said oil compartment.

A device of as character described comprising an 1-= tuhe provided with a vaeuous compar said X-ray tube being further prov with portions fashions. into a plurality of other compartments, insulating material disposed within said other compartments. transformers located within said other compartments and insulated by said insulating material contained therein, and connections for enabling said trasformers to cause a discharge to take place within said vacuous compartment.

3. A device of the character described comprising an X-ray tube provided with a discharge compartment and with a pair of transformer compartments, said discharge compartment being evacuated, a pair of cores of magnetic material one mounted in each of said transformer compartments, a pair of discharge terminals one being carried by each of said cores, said terminals extending into said discharge compartment, a pair of separate transformers mounted within said pair of transformer compartments each transformer being connected with one of said discharge terminals, and a quantity of insulating material contained in each of said transformer compartments for insulating the transformer therein contained.

4. A device of the character described comprising an Xray tube provided with a discharge compartment and with a pair of transformer compartments, a pair of discharge terminals extending into said discharge compartment, a pair of separate transformers each connected with said discharge terminals and each housed within one of said transformer compartments, and a quantity of insulating material contained within each of said transformer compartments for insulating the transformer therein contained.

5. A device of the character described comprising an X-ray tube provided with a discharge compartment and with a pair of transformer compartments, all of said compartments being separated from each other by insulating material, a pair of discharge terminals each extending into said discharge compartment, a pair of of separate transformers mounted within said transformer compartments and connected directly with said discharge terminals, and a quantity of insulating material contained within said transformer compartments for enveloping the transformers therein contained.

6. In a vacuum discharge apparatus the combination of a hollow member provided with an exacuated discharge compartment, a containing member provided with an oil compartment, a pair of high tension discharge electrodes located within said discharge compartment, onelof said electrodes having a portion extending into said oil compartment, connections from said high tension transformer to said discharge electrodes, and a body of oil contained within said oil compartment and in actual contact with the portion of said electrode extending thereinto, for the double purpose of cooling said last mentioned electrode and insulating said high tension transformer.

7. In an X-ray apparatus the combination of a hollow member provided with an evacu ated discharge compartment, a cathode and an anode located within said discharge compartment. said anode having a stem portion extending into said oil compartment, a high tension transformer housed within said oil compartment, connections from said I high tension transformer to said cathode and said anode, and a body of oil contained within said oil compartment and in actual contact with the portion of said anode extending into said oil compartment, for the double purpose of cooling said anode and insulating said high tension transformer.

' ARTHUR MUTSCHELLER.

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